Scientists spill the truth about drinking and your health.

Scientists spill the truth about drinking and your health.

I was so happy with the French paradox. This was the phrase researchers came up with in the early 1990s to explain the completely not-fair scenario of how the French were indulging in duck confit (duck cooked in lots of fat, a waiter once explained to me) and buttery croissants while not only remaining thin but also having fewer heart attacks. So not fair to Americans who were glumly gnawing broiled chicken breasts and low-fat cookies and buying increasingly outlandish books about losing weight, only to find themselves fatter than ever and just as likely to get heart disease.

But the French paradox offered a bonbon of hope. Some researchers suggested that the secret to French coronary health was, in part, the red wine sipped over the course of a long, leisurely dinner.

I began having wine with my dinner too. And even if I finished my second glass while hunched over the sink scouring pots, I still felt a bit of that French glamour. As if it were Edith Piaf wailing in the background, not Bruce Springsteen.

Then I heard someone say that drinking moderate amounts of any alcohol was good for the heart. While wine is thought to have hundreds of substances, such as resveratrol (an antioxidant found in the skin of grapes linked with cardiovascular benefits and cancer prevention), that favorably affect health, I, too, began reading the reports that suggested that any form of alcohol increases "good" cholesterol, decreases inflammation and "thins" the blood, making dangerous blood clots less likely. Lo, another door to the good life opened! I didn't learn to mix anything fancier than a vodka-and-tonic at home, but when my girlfriends and I went out we ordered drinks that were considerably more exotic, with silly names: the Coexistence Collins, the Rose of Warsaw, Bluebeard's Passion. (Surely, no one has more fun coming up with names than cocktail designers and breeders of thoroughbred racehorses.) It was easy to feel downright virtuous as we sipped our drinks, especially as we heard about new studies suggesting that moderate alcohol consumption also lessened the risk of stroke and increased bone density.

Here come the caveats…

Not everyone in the scientific community is so enthusiastic about the health benefits of moderate imbibing. Critics pooh-pooh the French paradox, saying that the French might have lower risks for cardiovascular disease but that they don't have significantly lower rates of overall mortality.

In fact, not all research suggests that moderate alcohol consumption confers health benefits. For example, multiple studies have shown an increased risk of breast cancer for women who drink even as little as one glass of alcohol per day, leading some researchers to conclude that when it comes to breast cancer, any level of consumption can be considered unsafe. Other research suggests that the B vitamin folate-found in leafy greens, oranges and legumes-and its supplemental form, folic acid, may blunt alcohol's breast cancer impact by supporting normal cell division and repairing DNA damage. One study found that women who drank alcohol did not have a higher risk of breast cancer if they consumed at least 600 mcg/day of folic acid.

"For people who have had breast cancer, or are at risk of getting breast cancer, and who drink, I do not insist on total abstinence. But I advocate that if you do drink, you should do so moderately," says Larry Norton, M.D., medical director of the Evelyn H. Lauder Breast Center of Memorial Sloan-Kettering Cancer Center in New York City. "That's a reasonable choice if you're eating lots of fruits and vegetables." (Fruits and vegetables provide nutrients, like folate and vitamin C, that may mitigate the cancer risk associated with drinking alcohol.)

However, even eating bushels of fruits and vegetables won't erase the ill effects of too much alcohol. Some scientists are concerned that ordinary people like moi have gotten the idea that if one serving of alcohol might be good, several more might be better.

"Either consciously or subconsciously, some people omit the word ‘moderate' and come away with the idea that drinking is good for you," says Tim Naimi, M.D., M.P.H., an epidemiologist at the Centers for Disease Control and Prevention (CDC). "The concept of moderate drinking tends to be adjusted elastically at the level at which one already drinks."

There's no quibble that excessive drinking is bad for every system and every part of our bodies. Although there may be some debate about the definition of moderate drinking-from half to two servings of alcohol per day for women, two to three for men-researchers are quick to point out that this is not a weekly average. We can't abstain from Sunday through Friday, have seven drinks on Saturday, and call ourselves moderate drinkers-that's binging. Both excessive daily drinking and binge drinking are harmful, leading to liver damage, inflammation of the pancreas, various cancers, high blood pressure, sleep disorders, accidents and violent behavior. There's nothing even slightly alluring about any of that.

And wanting to improve your health isn't a reason to start drinking alcohol, most experts emphasize. There's the issue that some people may have a history of alcoholism or predisposition that renders any level of alcohol intake dangerous. Some take medications that can cause serious health problems when mixed with alcohol. Finally, many experts argue that there really is no ironclad proof that one or two drinks daily improve anyone's health and longevity. "You have to take these studies with a big grain of salt," says Larry Norton.

At the heart of their caveats is this: most of the research studies on the health impacts of alcohol are observational. In this kind of research, large groups of people are studied for a long period of time, and their eating habits, their exercise patterns, their medications, their incomes and many other factors are tracked, along with their evolving health profile. Researchers look for links between lifestyle or environmental factors and certain health outcomes. Observational studies are valuable tools for the scientific and public health community. For instance, they were the first solid indication of the connection between smoking cigarettes and lung cancer. But since certain populations tend to have complicated clusters of either negative or positive behaviors, it's tricky to draw medical advice from their comparison. "When you look at the profiles of moderate drinkers, you see that they exercise, they eat lots of green vegetables, they have a glass of wine at dinner, and so on," says Tim Naimi of the CDC.

So is it the wine at dinner that's really making a difference? Or is it something else?

Glass still half full?

Researchers who conduct observational research believe that the level of consistency across different studies is highly compelling. They say they work hard to account for "confounding factors" (e.g., diet and exercise habits) that might skew the results. And sometimes, they're able to support the observed benefits with the findings of small clinical trials.

Take, for example, diabetes. Observational studies have linked moderate alcohol consumption with lower rates of diabetes among people at high risk for the disease, particularly those who are overweight. (This was initially surprising since it's well known that, in people who already have diabetes, drinking alcohol can cause blood-glucose levels to dip dangerously low or to spike alarmingly high.) One group of researchers followed up these observational studies with a small, three-month clinical trial that randomly split a group of nondrinkers with type 2 diabetes into two groups: one that received a daily "dose" of merlot or sauvignon blanc versus another that abstained. The moderate drinkers were able to control their blood-glucose levels better than the nondrinkers. Scientists still are trying to tease out the cascade of molecular events at work but it appears that, among other things, moderate alcohol consumption nudges fat cells to release a chemical called adiponectin.

"Adiponectin probably allows insulin to work more efficiently and do a better job of bringing glucose into our muscles and other tissues," says Eric Rimm, Sc.D., a Harvard epidemiologist who studies the connection between alcohol and health.

While scientists try to hone in on the biochemistry that explains the health benefits seen in older observational studies, new studies keep pouring in. Geriatrician Kaycee Sink, M.D., M.A.S., from Wake Forest University Baptist Medical Center, recently concluded what she believes is the largest, longest U.S. observational study to look at the effects of regular alcohol intake on dementia. She separated more than 3,000 seniors into current abstainers, light drinkers, moderate drinkers and heavy drinkers and evaluated them every six months for up to six years. At the conclusion of the study, moderate drinkers were 37 percent less likely to develop dementia than their nondrinking counterparts. The observed benefits of alcohol on the heart and brain are probably connected. To function optimally, the brain needs a healthy supply of blood, and it's believed that alcohol's beneficial effects on "good" HDL cholesterol may protect the brain as well as the heart. "Anything that's good for your heart is probably also good for your brain," says Sink.

To drink or not to drink?

Some experts recommend keeping our health profile and history in mind as we decide how much to drink. Young women with a family history of breast cancer might decide to keep their consumption very low or abstain completely. Middle-aged men with a family history of heart disease or dementia, on the other hand, might continue their evening cocktail or glass of wine with dinner with a clear conscience.

But other experts tell moderate drinkers not to let the barrage of studies overwhelm their joie de vivre. "My message to people who enjoy drinking moderately is to stop obsessing about whether it helps your health or not," says Tim Naimi. "You don't need an excuse to drink a moderate amount of alcohol."

I've decided to make a cocktail of these bits of advice. My family history is rife with heart disease, dementia and diabetes, but not much cancer. So I'll keep drinking, but remind myself that "moderate" is somewhat short of the number of drinks that inspire me to call my brother and sing Daffy Duck's Rhapsody. And when I pour myself a glass of red wine, I'll slough away the conflicting messages about alcohol as medicine with a Gallic shrug, inhale deeply, and enjoy!

November/December 2009